Larger HVAC blower available?
Thread Starter
Heel & Toe
Joined: Oct 2011
Posts: 16
Likes: 1
From: Fernandina Beach, FL
Larger HVAC blower available?
I live in Florida, and in the summer, the AC blower just doesn't put out enough air. The air is cold, there just isn't a high enough throughput. Is there a replacement blower available for a '71 which will deliver a higher throughput without having to make changes to the electrical?
Race Director
Joined: Nov 2006
Posts: 13,225
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
A blower motor from a 84 or 85 C4 corvette is plug and play wiring wise. You will need to make a spacer approximately 7/8th's of an inch thick but otherwise the mounting pattern is the same. Will roughly double the air output.
Lots of threads on here about C4 blower motor and spacer.
Lots of threads on here about C4 blower motor and spacer.
Race Director
Joined: Nov 2006
Posts: 13,225
Likes: 7,823
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Oh, I'm in Queensland Australia, Florida looks pretty chilly to me! And it's working great for me in my 77.
Safety Car
Joined: Dec 2012
Posts: 3,814
Likes: 1,723
From: Summerville SC
As said, a lot of us have changed over to a C4 blower. The adapter you need is easy to fabricate. And while you are there...you might be surprised to see all of the leaves and junk that has fallen inside the heater box, which might be restricting your air flow. 
Pro
Joined: Nov 2023
Posts: 701
Likes: 335
From: Aubrey TX
Is this the newer blower motor in question? If not, any recommendations are appreciated.
https://www.topflightautomotive.com/...ioner-77-late/
https://www.topflightautomotive.com/...ioner-77-late/
Le Mans Master
Joined: Aug 2006
Posts: 7,426
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
No, you want a C-4 motor
Zip # AH-273
The fan is longer and that is why you need a spacer.
Zip # AH-273
The fan is longer and that is why you need a spacer.
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Race Director
Joined: Nov 2006
Posts: 13,225
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Is this the newer blower motor in question? If not, any recommendations are appreciated.
https://www.topflightautomotive.com/...ioner-77-late/
https://www.topflightautomotive.com/...ioner-77-late/
Top Flight needs to be called on the carpet for this one! Absolutely NOT correct!
Melting Slicks
Joined: Jun 2011
Posts: 2,383
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From: Leland , North Carolina
Interesting, I may do this.
Melting Slicks
Joined: Aug 2004
Posts: 2,907
Likes: 229
From: Oakbank Manitoba
You might see better performance by simply swapping out the ground wire at the fan for a larger gauge wire. When the fan is set to "high" the hi speed relay flips over to the 12ga power wire delivering more current to the fan. Unfortunately the ground wire at the fan is only 16ga wire. This was a design flaw. Try this modification first before changing out your fan. For high speed to work correctly it should also have a 12ga ground wire.